Author Topic: Help with steering ratios  (Read 2929 times)

mikefam

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Help with steering ratios
« on: June 25, 2016, 11:01:09 PM »
I am trying to identify replacement steering parts for my 68 standard convertible and can use some help.

When I got the car it had two different length steering arms and I replaced the shorter of the two with a longer one to make a matching set. I do not know the significance of the two different steering arms....maybe different years....different ratios?? The steering arms now match and the steering wheel is now just about exactly three turns from stop to stop.

While shopping for steering linkage parts I have learned that the pitman arm is available in three lengths, 5 3/8 for the standard steering gearbox, 5 7/8 for the quick ratio steering gearbox and a 5 3/4 which I can't identify yet. My pitman arm is 5 7/8 center to center.

Now to my question - has anyone made sense of this mix of parts? I would appreciate anything that anyone can tell me about the different steering arms, pitman arms and steering boxes. Is my three turn steering quick ratio? Standard ratio? Mid ratio?

Thanks for any help, Mike.

68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Help with steering ratios
« Reply #1 on: June 25, 2016, 11:56:09 PM »
I should have mentioned that I have power steering.

At this point my best guess is that I should have the long 5 7/8" pitman arm (which I do) and the short steering arms (which I do not). When I installed the two long steering arms years ago the short arms were not available in repro. They are available now but I don't see how it's necessary to change them. What do you guys think?

Mike.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Help with steering ratios
« Reply #2 on: June 30, 2016, 01:42:41 PM »
For the record
the best that I can come up with word of mouth around the internet:

Power assist steering
Quick ratio = 5 7/8" ptiman arm and short steering arms
Standard ratio = 5 3/8 pitman arm long steering arms

Non power assist steering
Quick ratio = 5 3/4" ptman arm and long steering arms
Standard ratio = 5 1/4" pitman arm and long steering arms

I havn't found whether the steering box ratio is the same or different on each.

Mike.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

Ramjett54

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Re: Help with steering ratios
« Reply #3 on: July 02, 2016, 04:25:34 PM »